Casings often need to be cut underwater, in situ. At times, portions of tubulars, e.g. casings or wellheads, need to be removed, such as when a well is abandoned. Often this is a difficult task.
Although standard, e.g. off-the-shelf type, tools are available, interfacing the various tools to platforms or tools needed to effect the cutting and removal is often difficult and often requires some degree of customization.